Ultrasound Calibration for Dual-Armed Surgical Navigation System.

Ultrasound (US) imaging system is widely used in robotic systems for precision positioning in clinical applications. The US calibration is critical to minimize the difference of spatial coordinates between instruments, for minimally invasive surgery (MIS) in navigation systems. In this study, we propose a dual robotic arm system that combines US imaging with one arm for path planning and monitoring and accurate positioning with the other arm for instrument placement via the preplanning procedures. A phantom with N-wire and N-wedge was designed for US calibration. The US calibration showed a mean error of 0.76 mm; the mean dual-arm calibration error is 0.31 mm. The positioning error of the system was verified with a mean error of 1.48 mm. In addition, we used two abdominal phantoms with computed tomography scan validation, with an averaged position error of 1.867 ± 0.436 mm and an orientation error of 2.190 ± 0.764°. The proposed system is aimed to perform clinical operations, such as abdominal MIS, with real-time image monitoring of the organ tissues and instrument positions, which meet the requirements for medical application.

Swallowing Training Combined With Game-Based Biofeedback in Poststroke Dysphagia.

BACKGROUND: For patients with dysphagia due to stroke, in addition to compensatory strategies, exercises are used to help improve motor function. Biofeedback is used in neuromuscular training and is promising for swallowing training. OBJECTIVE: To evaluate the functional value of game-based biofeedback in swallowing therapy for patients with poststroke dysphagia. DESIGN: A case-control study. SETTING: Academic tertiary hospital. PARTICIPANTS: Subjects with poststroke dysphagia (n = 20) were individually matched to 2 separate groups, a game-based biofeedback group (n = 10) or a control group (n = 10), for age, gender, duration of dysphagia, and dysphagia grades. INTERVENTIONS: Each participant underwent 1-hour sessions 3 times per week for a total of 16 treatment sessions. Each session included a 30-minute session of traditional swallow treatment and a 30-minute session of laryngeal elevation exercises. In the experimental group, laryngeal elevation exercises were combined with additional game-based biofeedback. MAIN OUTCOME MEASURES: Outcomes assessed before and after interventions included hyoid bone displacement, Functional Oral Intake Scale (FOIS) scores, and nasogastric (NG) tube removal rate. RESULTS: Intergroup analyses showed larger differences in hyoid bone displacement and FOIS scores (before and after treatment) in the experimental group than in the control group, with statistical significance (P = .007 and P = .014, respectively). Intergroup analyses showed that the hyoid bone displacement change and FOIS scores before and after treatment exhibited statistically significant improvement only in the experimental group (P = .002 and P = .004, respectively). In all, 8 of 10 patients (80%) in the experimental group and 2 of 10 patients (20%) in the control group discontinued NG tube insertion after therapy. Participation in the experimental group was associated with an increased probability of tube removal (odds ratio = 6.00; 95% confidence interval = 1.08-33.27, P = .009). CONCLUSIONS: Laryngeal elevation training combined with game-based biofeedback augments the change in hyoid bone displacement and FOIS scores, and increases the NG tube removal rate in patients with poststroke dysphagia.

Effect of a 5-HT(1A) receptor agonist (8-OH-DPAT) on the external urethral sphincter activity in the rat.

BACKGROUND/PURPOSE: This study examined the effects of a 5-HT(1A) receptor agonist (8-OH-DPAT) on external urethral sphincter (EUS) activity in urethane-anesthetized rats. METHODS: An EUS electromyogram (EMG) and intravesical pressure (IVP) were simultaneously recorded during continuous cystometrographic monitoring, to provide a quantitative evaluation of EUS activity and urethral urodynamics of voiding. RESULTS: When examining the EUS burst activity, durations of the active (AP) and silent periods (SP) as a function of the time axis, respectively, exhibited concave- and convex-shaped curves. The burst discharges of the EUS-EMG were divided into nonvoiding and voiding burst activities based on the oscillation waves of the IVP, which were located in Phases 1 and 2 of the IVP. After 8-OH-DPAT treatment, the entire burst period in Phases 1 to 2 of the IVP was significantly prolonged. The average SP in both Phases 1 and 2 significantly increased but the average APs were not affected. Urodynamic results showed decreases in the volume threshold, contraction amplitude, and residual volume as well as an increase in the contraction duration. In addition, the amplitude of bladder high-frequency oscillatory waves in the IVP and the average urethral flow rate were reduced, but the entire voiding efficiency increased. CONCLUSION: The influences of 8-OH-DPAT on EUS burst activity and urodynamics were exactly detected by the sophisticated EMG analytic design, and the results could be a reference for the pharmacological treatment of patients with lower urinary tract dysfunction.